Pfizer said on Thursday it was recalling all lots of its anti-smoking treatment, Chantix, due to high levels of cancer-causing agents called nitrosamines in the pills.
The drugmaker paused distribution of the drug in June, and has already recalled a number of lots of the medicine so far.
Pfizer asked wholesalers and distributors on Thursday to stop the use and distribution of the tablets immediately.
The company said there was no immediate risk to patients
taking Chantix, but advised them to consult with their health care provider to check the availability of alternative treatments.
Chantix was approved by the FDA in May 2006 as a prescription medication to help adults aged 18 and over quit smoking and is typically used for 12 to 24 weeks.